How it was done Senior colourist Asa Shoul used Baselight with a combination of custom filters and layers to enhance the soft-contrast period design.

Often set in low-light slums, Shoul retained detail in the costumes by making sure the blacks were not buried. Sets such as the convent and community hall repeat throughout the series, but with each episode introducing new characters and sets, it provided an opportunity for fresh elements to be used.

Shoul performed two passes on an episode on the first day of grading, with a third taking place the next day, followed by a review with programme execs and a final tweak in the afternoon.